Expanding mandrel.



w, P. AIKIN. EXPANDING MANDREL.

APPLICATION FILED DEC. l0. l9l7.

Patented June 18, 1918.

Jw W ED STATES PAT OFFICE.

wILLIAM P. AIKIN, 0F WATEBTOWN, NEW YORK, ASSIG-NOB TO INTERNATIONAL 3m CORPORATION.

EXPANDING MANDREL.

Specification of Letters Patent.

Patented J une 18, 1918.

To all whom it may concern:

Be it known that I, WILLIAM P. AJKDI, a citizen of the United States, residing at Watertown, in the county of Jefferson and State of New York, have invented certain new and useful Im rovements in Expanding Mandrels; an I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to new and useful improvements in mandrels for burs, for the purpose of redressing the surfaces of pulp grind-stones, and consists in the provision of expanding means upon the mandrel for holding the bur securely in place thereon.

The present invention consists of various details of construction, combinations and arrangements of arts which will be hereinafter fully descri 'ed, shown in the accompanying drawings and then specifically defined in the appended claims.

I illustrate my invention in the accompanying drawings which, with the letters of reference marked thereon, form a part of this application and in which:

Figure 1 is a central sectional view through a mandrel and bur.

Fig. 2 is an end view, and

Fig. 3 is a view showing the parts disassembled.

Reference now being had to the details of the drawings by letter:

A and B designate two mandrel sections, the former of which has an elongated shell portion C 'circumferentially threaded, and about which the section B, which is interiorly threaded, is adapted to be mounted. This section A is provided with a beveled flange E, and F designates a cylindrical split ring, with an interior beveled portion H. Said ring F fits over the circumference of the mandrel section A and is adapted to have a wedging action against the beveled flange E. The mandrel section B has a beveled shoulder N, and O designates a. split ring similar to the ring F, having a beveled portion T, adapted to have a wedging action against the inclined shoulder upon the section B. The adjacent ends of the two ring sections are adapted to contact with each other as the mandrel sections are screwed together, thus serving to expand the rings and cause the circumferences thereof to frictionall engage the bore of the bur. The outer ace of the section B is provided with holes S, for the reception of a.

wrench whereby the section B may be turned. A roller bearing member K is placed within the bore of the mandrel sections and forms a bearing therefor.

In assembling the parts, the mandrel section A is placed upon the base, provided with projecting prongs fitting the holes upon the end thereof and by applying a wrench or other tool in the member B, the two mandrel sections may be tightened, so that the circumference of the split ring will frictionally engage the bore of the bur. The roller bearing is then inserted within the mandrel sections, after which the roller bearing is placed upon the fork which is attached to, or is a part of, the pulp mill lathe, the fork havin a pin M of a suitable size to hold the man rel or bur. The 0 erator will then screw the lathe up, unti the bur comes in contact with the rapidly rotating grind stone, and which in turn causes the bur and mandrel to revolve rapidly in the opposite direction, leaving the imprint on the surface of the grind stone corresponding approximately to the cut of the What I claim to be new is:

1. An expanding mandrel for burs comprising two hollow sections having threaded connection with each other, and each hav ing a cylindrical circumference with a flarin beveled flange portion at its outer end, spit rings with their inner faces cylindrical, one mounted upon each section and adapted to engage the cylindrical circumference thereof, said rings having beveled portions adapted to have a wedging action against the beveled flanges of said sections, and means upon one of said sections for limiting the lateral movement of the shell of a bur thereon.

2. An expanding mandrel for burs comprising two hollow sections having threaded connection with each other, and each having a cylindrical circumference with a flaring beveled flange portion at its outer end, split rings with their inner faces cylindrical, of a bur, and serving to limit the lateral 10 one mounted upon each section and adapted movement of the latter in one direction. to engage the cylindrical circumference In testimony whereof I hereunto aflix my tlae'reofCi said1 rings having beveled portions signature in presence of two witnesses. 5aate toaveawegin actionaainst the lieveled. flanges of said sections, th e bev- WILLIAM AIKIN' eled portion on the circumference of one of Witnesses: said sections terminating in a cylindrical A.'H.- Rnc'ron, shoulder adapted to be engaged by the shell F. W. N. 

